1. Field of the Invention
The present invention generally relates to potato storage buildings in which large quantities of potatoes are stored with vent pipes positioned below the potatoes introducing conditioned air into the stored potatoes. More specifically, the present invention involves a structural arrangement in which a fan house is constructed to accommodate an evaporative cell, fan and other related equipment which may be used to provide conditioned air with the fan house being oriented internally of or within the confines of a curvet (Quonset) building or air plenum to reduce the overall cost of the building and to provide an assembly that is easier to design from an engineering standpoint than an external fan house for a curvet (Quonset) style building. The fan and evaporative cell may be arranged in various relationships to each other and with an air plenum and vent pipe arrangement with the essential arrangement being the provision of the fan house within the interior of the curvet style building.
2. Description of the Prior Art
Commercial or seed potatoes are conventionally stored in buildings or cellars with the quantity of the stored potatoes typically ranging anywhere from 10,000 hundred weight to 500,000 hundred weight. When storing such potatoes, vent pipes of relatively large diameter having air discharge holes are placed along the floor of the storage building so that conditioned air having desired temperature and moisture characteristics passes through the vent pipes and is discharged through the holes into the stored potatoes. Various types of buildings are employed but usually, an air plenum extends throughout the length of the building and connects to the vent pipes. Usually, the volume of air passing through the air plenum and vent pipes ranges between 10 cu. ft. per ton of potatoes per minute to 20 cu. ft. per ton of potatoes per minute. The moisture content can be ambient moisture or added moisture up to approximately 96% humidity. The air plenum can be typically located on the outside of the building or can be incorporated into the interior of the building. A fan and evaporative cell are located in a fan house which is the area designated to receive the fan and evaporative cell and one or more humidifiers and controls. The evaporative cells used are typically constructed of cellulose paper impregnated with insoluble anti-rot salts and rigidifying saturants and constructed for evaporative cooling with water dripping down through the cell and air being blown through the cell to pick up the moisture and to provide evaporative cooling. The cells may be on the order of 1 ft. thick and may range between 20 sq. ft. of cooling surface area up to over 300 sq. ft. of surface area. The buildings may be of various constructions such as straight wall buildings, slope wall buildings, dirt/pole buildings and curvet style buildings. Essential factors in proper storage of potatoes is humidity and temperature control which is greatly aided by the use of evaporative cells which assist in the introduction of humidity and the evaporative cooling process assists in temperature control since the evaporative cell can cool air supplied to the vent pipes from 10.degree. to 15.degree. depending on the temperature and humidity of ambient air. The introduction of conditioned air into the bottom areas of the stored potatoes keep the potatoes from shrinking and keeps the potatoes cool since the conditioned air is circulated up through the potato pile and then either exhausted out exhaust vents or recirculated back through the evaporative cell and fan.
U.S. Pat. No. 3,921,508 to Merson discloses potato storage buildings of arcuate or curvet style in which an air plenum extends longitudinally between two adjacent buildings with an external fan house being provided at one end of the buildings for circulating air through the plenum and potatoes.
The prior art in this field of endeavor does not disclose an internal fan house constructed to accommodate an evaporative cell unit and a fan unit within the confines of a curvet style building or air plenum with it being noted that the Merson patent discloses a fan house projecting outwardly from the building.